In recent years, the number of automobiles each provided with a curtain airbag device has been increasing. This curtain airbag device includes a curtain airbag which inflates and deploys along a side window portion of a vehicle body in the vehicle interior in order to protect the head of an occupant in vehicle accidents such as a side impact and a rollover.
Ordinarily, when an accident such as a side impact or rollover on a vehicle is detected or such an accident is predicted in the curtain airbag device an inflator generates an inflation gas and supplies the gas to the inside of the curtain airbag from the inflator, thereby, causing the curtain airbag to instantly inflate and deploy in the vehicle interior. Accordingly, the inflating portion of the curtain airbag protects the head of the occupant, thus ensuring the safety of the occupant.
Japanese Patent Application Laid-open No. 2012-201312 (Patent Literature (hereinafter, referred to as “PTL”) 1) discloses an invention relating to such a curtain airbag device. Curtain airbag device 60 disclosed in PTL 1 includes curtain airbag 70 and inflator 61 which generates a gas and supplies the gas to the inside of curtain airbag 70, as illustrated in FIG. 10.
Curtain airbag 70 in PTL 1 includes: airbag body 71 which is supplied with a gas and thus inflates; and a plurality of attachment pieces 72 attached to an upper end portion of airbag body 71. Curtain airbag 70 described above is fixed to vehicle body 80 using attachment pieces 72 each fixed to vehicle body 80 using a fixing member such as a bolt. Thus, airbag body 71 is housed in a state of being folded in a range extending from front pillar 81 to the vicinity of rear pillar 83 through roof-side portion 82 of vehicle body 80.
In addition, airbag body 71 of curtain airbag 70 includes: a main inflating portion (main chamber) 73 which inflates and deploys in the head protection area; and front and rear auxiliary inflating portions (second chambers) 74a and 74b in communication with main inflating portion 73 via a reduced-diameter portion. In addition, main inflating portion 73 includes: front main inflating portion 73a for front seat; rear main inflating portion 73b for rear seat; and gas supply passage 73c which serves as a gas passage communicating between front main inflating portion 73a and rear main inflating portion 73b along roof-side portion 82.
In curtain airbag 70 disclosed in PTL 1, in particular, front main inflating portion 73a of airbag body 71 is formed so as to deploy in a cylindrical shape extending in a vehicle longitudinal direction above the belt line (also referred to as “trim line”) drawn by a lower edge of a side window, so as to overlap with center pillar 84 when viewed in a side view of the vehicle.
Front auxiliary inflating portion 74a is disposed so that the lower end portion of front auxiliary inflating portion 74a extends below the belt line and overlaps with the front side door in front of main inflating portion 73 in a side view of the vehicle when front auxiliary inflating portion 74a deploys. In addition, rear auxiliary inflating portion 74b is disposed so that the lower end portion of rear auxiliary inflating portion 74b extends below the belt line and overlaps with the rear side door under gas supply passage 73c between front main inflating portion 73a and rear main inflating portion 73b in a side view of the vehicle when rear auxiliary inflating portion 74b deploys.
According to PTL 1, in a side impact on a vehicle, main inflating portion 73 of curtain airbag device 60 deploys upon receiving a supply of gas, so that the head of an occupant can be protected from the side impact. Meanwhile, in a vehicle rollover, main inflating portion 73 and front and rear auxiliary inflating portions 74a and 74b deploy, so that the head of the occupant can be restricted from moving outward in the vehicle width direction within a broad range of the vehicle longitudinal direction.
In PTL 1, in particular, front main inflating portion 73a is supported by center pillar 84 and front and rear auxiliary inflating portions 74a and 74b are supported by the side door below the belt line in a rollover. Thus, the reaction force that restricts the head of the occupant from moving outward in the vehicle width direction can be effectively acquired, and the protection performance for the head of an occupant improves.